Automatic firearm



Aug. 1.0, 1937. E. sTEcKE AUTOMATIC FIREARM Filed June 30, 1934 PatentedAug. 10, A 1937 UNITED STATES AUTOMATIC FIREABM Edward stecke, Warsaw,Poland In Poland July 8, 1933 Application Juneau; 1934, seranV No.133,233

The present invention relates to automa-tic ilrearms, for instance,machine guns and has i'or its object to provide an automatic gun havinga stationary barrel, no gas chamber, and a breech block which is lockedduring the ring.

Automatic ilrearms are known in which the gas pressure in the gun barrelis utilized for actuating the breech block. Such guns have thedisadvantage that it is necessary to lubricate the cartridge cases asexperience shows that the frictional resistance of a non-lubricatedcartridge case relatively to the barrel chamber at the fmoment ofmaximum pressure in the chamber,

is greater than the pressure on the bottom o! the cartridge. Anautomatic gun according to the present invention is free from thisdrawback and there is no need to lubricate the cartridge cases.

According to the invention a slidable member is provided and connectedwith the breech block in such a manner that a very small return rear-/ward movement oi the locked breech block produces a comparativelyconsiderable displacement of the said movable member.` The kinetic en-F25 ergy of the movable member is transmitted at the end of the strokeof this member to the breech block. The breech block is then furthermoved rearwardly with very considerable force. Atpthe same time thecartridge case is reliably pulled out of the barrel chamber, even thoughthe cartridge is not lubricated. 'In this manner it will thus be seenthat the breech block mechanism is not operated by the pressure oi p thegases remaining in the barrel after the firing,

but is actuated by utilizing 'the pressure which exists in the barrelchamber before the bullet leaves the barrel.

In order to obtain a considerable displacement oi the movable memberduring a. first short rear- 40 ward movement of the breech block, thebreech block is, according to the invention, provided with a suitablemechanism which preferably consists of two slidable and turnabletwo-armed locking levers. In the position of rest of the breech block,that is to say, the position occupied before firing, the outer arms ofthe locking levers bear against inclined walls of suitable recessesprovided in the gun chamber, whilst the inner arms rest upon the memberslidable in the breech block.

Within an extension of the breech block there may also be provided afurther set of two-armed levers, the outer arms of which are adapted tobear against recessed portions of the gun chamber, whilst the inner armslie within the path of the member slidable in the breech block. vBy thismeans it is possible to obtain a very powerful and considerable rearwardmovement of the breech block and simultaneous withdrawal of thecartridge case from the bullet chamber. This 5 is attained by themovable slide member within the breech block striking against the innerarms o! the second set of levers. At the same time,- that is at'thecommencement of the second part of the movement of the breech blockcaused by 10 the impact of the sliding member, as the rst set of levers,that is the locking levers, is released so as to entirely unlock theYbreech block. The

locking levers slide' during this release movement into the breech blockunder `the action oi inclined walls provided in corresponding recessesin the gun chamber. i

The accompanying drawing shows by way of example one constructionembodying the features of the invention. 20

Fig. l is a sectional elevation through the breech block and theadjacent parts of an automatic gun,

Fig. 2 is a longit dinal section partly in plan showing the parts in theposition they assume 25 before the iirin'g, l

Fig. 3is a longitudinal section showing the parts in the position theyassume after the tiring.

Fig. 1 is drawn to a slightly smaller scale than Figs. Zand 3. Y 30Within the gun chamber I5 is slidably mounted a breech block 4I providedwith a known device 1 for withdrawing the cartridge case i'rom thebarrel chamber. Within the breech block I is slidably mounted a member3. The breech 35 block I is locked in the ilring position by means oftwo twoarmed levers 2, the outer arms of' which bear against inclinedwalls 8 of recesses formed in the gun chamber I5, whilst the inner armsof the levers bear upon the plane face IB of 40 the slidable member 3.The latter member has a cylindrical supporting part I1 and is movedIorward and against the levers 2 by a spring 4. l

At the, moment of firing, the breech. block moves backwards. At the sametime thelocking 45 levers 2 turn owing to the pressure exerted upon themby the walls 8, about points Li'representin at that moment thefulcrll/rty/{he levers trike the walls of the cylindrical p t II of thes iding member 3 limiting their t ing movement. Dur- 50 ing this turningmovement of the locking levers, which is very rapid, the inner arms ofthe locking levers act upon the plane face I6 of the movable slidemember 3 and throw the slide backwards with considerable velocity. 55

This backward movement of the slide 3 completely releases the lockinglevers 2 as shown in Fig. 2. The locking levers then slide alonginclined walls 8 of the gun chamber I5 and enter into suitable recesseswithin the breech block, touching in this position. the point 9 of thestriker pin, and entirely releasing the breech block I.

Simultaneously with the release of the breech block I,.the movable slidemember 3 is thrown against the innerarms of the two-armed leversA 5pivotally mounted at lil in the breech block and having the outer armsextending into recesses 6 of the gun chamber. Owing to the impact of themovable slide member 3 against the levers 5, the kinetic energy of theslide member is transmitted to the block and a very powerful rearwardmovement of the block is produced. The high ratio transmission of thelevers E produces a powerful Y rearward movement oi' thebreech block I,where-V by the cartridge case is loosened by an extractor 'l `in thebullet chamber I3, this being an essential condition for faultlessoperation of the gun. This powerful movement of the breech block rendersit unnecessary to lubricate the cartridge V4cases. l

The slide member 3 may be manually operated ,0 inner arms and saidslidable member having `a plane face and a cylindrical supporting partoper-l able by said inner arms, whereby during a short initial rearwardmovement of the breech block, said locking levers are turned by saidinclined walls and are caused after the contact with the cylindricalpart to throw said sliding member backwards with their inner arms; andmeans for transmitting the kinetic energyv of the thrown back slidingmember to the breech block for the purpose of causing a further backwardmovement of the breech block, substantially as described.

2. vIn an automatic gun the combination of: a casing; a cartridgechamber in said casing; a breech block chamber in 'said casing; a breechblock slidable in said breech block chamber and are caused to throwbackwards the sliding member within the breech block, whereupon thebreech block is further thrown back by the impact of the slidingmemberLsubstantialiy as describedl 3. In an automatic gun thecombination of aY casing; a cartridge chamber in said casing; a breechblock chamber in said casing; a breech block slidably mounted in saidbreech block chamber and provided with a cartridge extractor;

- a member slidably mounted within said breech block and having a planeface and a cylindrical supporting part; two symmetrical double-armedlocking levers slidably and turnably mounted in said breech block andhaving outer arms engaging the inclined walls of recesses in said casingin the locked position of the breech block, the inner arms of saiddouble-armed locking levers being prevented' from sliding inwardly bythe cylindrical supporting part of said sliding member and bearing inthe locked position of the breech block against the plane face of thesliding member; double-armed levers pivotally mounted at the end of thebreech block; recesses in the casing, into which extend the shorter armsof saidvdoublearmed levers; the longer inner arms of said double-armedlevers projecting inwardly into the path of the sliding member; springmeans tending to move the breech block into its forward position;whereby during a short initial rearward movement of the breech blockafter ring, the two locking arms are caused to turn under the action ofthe inclined surfaces within the casing, so as to throw backwards thesliding member within the breech block, whereupon the thrown backsliding member impacting against `the rear side of said double-armedlevers produces a powerful further rearward movement of the breech blockand entirely releases the locking levers, substantially as described.

EDWARD STECKE.

